The present invention relates to a novel polymer compound comprising 2,2,6,6-tetramethylpiperidine derivative-bonded monomer unit. More specifically, it relates to a novel polymer compound comprising 2,2,6,6-tetramethylpiperidine derivative-bonded monomer unit useful as an antioxidant for a dye-fixing element and a silver halide photosensitive material.
It has been well known that a dye, a dyestuff or a polymer substance (for example, rubber, plastic, etc.) is deteriorated by an oxidation reaction with which oxygen in air is concerned. Therefore, various deterioration prevention agents have been developed. As these antioxidants, various compounds such as phenols, hydroquinones, etc. have been known.
These conventional deterioration prevention agents, however, are not satisfactory in their performance as deterioration prevention agents of a dyestuff, a dye and a synthetic dye. Thus, the development of a new antioxidant has been desired. While, as a polymer compound having 2,2,6,6-tetramethylpiperidine derivative structure, for example, the compound described in JP-B-58-45696 (The term xe2x80x9cJP-Bxe2x80x9d as used herein means an xe2x80x9cexamined Japanese patent publicationxe2x80x9d) can be mentioned. The compound disclosed in this reference, however, was not assured to have sufficient stability and deterioration prevention effect and, therefore, the compound was desired to be improved.
An object of the present invention is to provide a novel polymer compound comprising 2,2,6,6-tetramethylpiperidine derivative-bonded monomer unit.
Another object of the present invention is to provide a novel polymer compound comprising 2,2,6,6-tetramethylpiperidine derivative-bonded monomer unit useful as a deterioration and fading prevention agent of a dyestuff and a dye.
The present inventors have conducted extensive study and research effort. As the result, the present inventors found a polymer compound comprising 2,2,6,6-tetramethylpiperidine derivative-bonded monomer unit represented by the following formula (A) and/or formula (B) and found that such a compound had an excellent deterioration prevention effect. 
Wherein R11 and R21 each represents a hydrogen atom, an oxy radical group, an alkyl group, an alkenyl group, an alkoxy group or an acyl group; R12 and R22 each represents a hydrogen atom or an alkyl group; Y1 and Y2 each represents ←CONR4xe2x80x94, ←COOxe2x80x94 or ←CH(OH)CH2Oxe2x80x94; Xxe2x88x92 represents a chlorine ion, a bromine ion, an iodine ion or a hydroxy ion; Z represents an atom group necessary for forming a 5- to 7-membered heteroring together with a nitrogen atom; R13 and R23 each represents a hydrogen atom, a methyl group, an ethyl group or a halogen atom; R4 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ← represents a bond of a main chain side of the polymer.